At first glance, a book on "Design by Composition for Rapid Prototyping" may seem out of place in a series on Robotics. However, this work has a couple of strong connections to the field of robotics and the robotics community, and I am delighted to introduce it to the series. The first connection is the motivation behind Binnard's work. Michael Binnard came to Stanford after having done his Masters thesis at the M.LT. Artificial Intelligence Lab, where he designed and built small walking robots, such as Boadicea (http: //www.ai.mit.eduJprojects/boadicea/).At M.LT. he observed first-hand how difficult it is to align, connect and support standard actuators, sensors, and processors in small mobile robots. Figure lea) below shows how complicated it is just to connect a simple motor to one link of a robot leg using conventional methods. Surely there had to be a better way Shape deposition manufacturing, an emerging rapid prototyping process, offered a possible solution. Actuators, sensors, processors and other components could be embedded directly into almost arbitrary three-dimensional shapes, without any of the fasteners and couplings that complicate the design in Figure lea). The process makes it possible to construct integrated robotic mechanisms, such as the example shown in Figure 1 (b) and the additional examples found in Chapters 7 and 8 of this monograph.

The material in this book is based on the assumption that new manufacturing techniques offer potential benefits to electromechanical designers, but that appropriate design systems are necessary. The book describes a design paradigm, 'design by composition', that facilitates design of integrated electromechanical devices for fabrication with novel rapid prototyping processes. New manufacturing techniques called layered manufacturing, rapid prototyping, or Solid Freeform Fabrication (SFF) build parts by a sequence of deposition and shaping operations. These techniques allow a greater degree of manufacturing automation, and offer new design possibilities. For example, during SFF fabrication, the interior of parts is accessible. Traditional manufacturing techniques, on the other hand, generally of parts with complex internal geometry and embedded components. The design by composition technique is particularly well suited to design and fabrication of mechanical parts with embedded electronic, sensor, and actuator components.The highly integrated mechanisms that can be fabricated with the Shape Deposition Manufacturing (SDM) process and the design by composition approach can result in small robotic systems with increased performance and reliability. The book describes some of the new possibilities offered by SFF techniques, in particular the SDM process, and how design by composition makes these capabilities accessible to designers. The book presents the concept of design by composition, as well as the theoretical development of algorithms for its implementation. A prototype implementation is described, as well as some example parts built at Stanford University with the system.